Hebrews 9 (The Message)
16-17 Like a will that takes effect when someone dies, the new covenant was put into action at Jesus' death. His death marked the transition from the old plan to the new one, canceling the old obligations and accompanying sins, and summoning the heirs to receive the eternal inheritance that was promised them. He brought together God and his people in this new way.
The new covenant becomes effective only after the death of Jesus has occured, not before. When Jesus was on earth, He was still under the law but He was demonstrating a lifestyle of the coming new covenant (e.g.like healing, performing miracles, not condemning or stoning to death the woman caught in adultery) that will take effect soon after His death. In the latter example, Jesus did not dispute the law of the old covenant that a person caught with adultery had to be stoned (condemned) to death. The interesting twist is that the religious people who condemned the woman could not even follow fully the law themselves. When Jesus confronted them by asking 'who is without sin to cast the first stone', the result was - one by one left her until she was left with Jesus. No one can ever keep the law, not even the religious pharisees! So why try?
Jesus demonstrated the New Covenant of grace to her by not condemning her but instead advising her to sin no more.
In the final analysis - So, when we read the bible, especially the books of the gospels when Jesus was still on earth, Jesus had to obey the laws as the new covenant was not in effect yet. Whilst He had to uphold the law by obedience to the law, He demostrated in his works the coming new covenant. This has caused a lot of confusion and contention about what is new and old covenant and has resulted in a mixture of law (old covenant) and grace (new covenant) in our walk with Jesus. Whenever we have some laws or regulations in our christian walk, those laws or regulations will soon catch up with us to condemn us, for the reason that none of us can ever follow the laws or regulations fully,not even those we set for ourselves such as the so called, spiritual self discipline (self effort-flesh). This is the main reason how condemnation and guilt comes in and then..... we wonder why we struggle with condemnation in our christian walk.
The goodnews is that the Jesus died 2000 yrs ago, shed his blood so that the new covenant can take effect and which is for us now, right at our door step, to empower us to walk a life of no condemnation. Jesus is the answer.